Shining light on osmosis holds hope for renewable energy
Light could hold the key to harnessing osmosis as a viable energy source according to Swiss researchers. Recently tested under real-world conditions, the findings offer hope for renewable energy that does not rely on specific weather conditions in contrast to wind and solar.
Recreating the conditions at estuaries, the researchers shined light on a system combining water, salt and a membrane to generate electricity. Under the effect of light, the system produces twice as much power as it does in the dark. The research findings have been published in the scientific journal JouleExternal link.
The way it works is that a low-intensity laser light releases embedded electrons and causes them to accumulate at the membrane’s surface, which increases the surface charge of the material. According to the researchers, a system of mirrors and lenses could be used to direct this light onto the membranes at river estuaries. Similar systems are used for solar photovoltaics.
Osmosis is a natural process whereby molecules migrate from a concentrated to a more diluted solution across a semi-permeable membrane. At river estuaries, osmosis happens when electrically charged salt ions move from the salty seawater to fresh river water.
“Essentially, the system could generate osmotic power day and night,” explains Michael Graf, the lead author of the paper on the EPFL website. “Output would double during daylight hours.”
This builds on LBEN researchExternal link published in 2016, which demonstrated the role of nanomaterials in producing osmotic power. To achieve high power generation, the researchers had to operate in an alkaline environment, with high pH levels that are far from the levels found in estuaries.
This time around, instead of using chemical treatments, the researchers discovered that light could be used, allowing them to operate in real-world conditions.
The potential
This could unlock significant opportunities for renewable energy production. In contrast to most renewable power technologies, like wind and solar, that are weather dependent, the method being developed at EPFL captures an energy source that’s constantly available at river estuaries: osmotic power, also known as blue energy.
The team indicates that there is still a lot of work to do before the technology can be used for real-world applications including stabilising the membrane.
First large-scale alpine solar plant approved in Switzerland
This content was published on
The approval was met with satisfaction by the project's organisers, but it also brings with it a certain amount of pressure.
Medieval squirrels may have ‘helped spread leprosy’
This content was published on
An examination of squirrel remains in the United Kingdom has opened up interesting questions and possibilities in terms of the history of the disease.
Swiss money laundering office registers record number of reports
This content was published on
The Money Laundering Reporting Office Switzerland (MROS) registered a record number of reports of suspicious activity last year.
Two teens accused of planning terror attack released from custody
This content was published on
The Schaffhausen judiciary has released the two teenagers from custody who allegedly planned bomb attacks in Switzerland.
If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at english@swissinfo.ch.
Read more
More
Renewables: Switzerland waiting for Godot
This content was published on
The Swiss approach to boosting renewable energy is far too passive and slow, finds a specialist for environmental science and management.
This content was published on
An underground research laboratory to investigate the long-term use of geothermal energy has opened in the southern Swiss Alps.
You can find an overview of ongoing debates with our journalists here . Please join us!
If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at english@swissinfo.ch.